It houses the remains of a 17th-century version of the Titanic.

This striking royal residence is the largest Renaissance-style castle in Scandinavia.

This Danish castle is supposedly haunted by a woman too independent to not be a witch.

Nordic giants resurrected from the sea and restored to their former greatness.

The gilded, masterful astronomical clock will calculate time, dates, and planetary positions for thousands of years to come.

Old Danish castle immortalized in Shakespeare's Hamlet.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Copenhagen's celebrated theme park and gardens.

A contemporary art installation housed within a Gothic cathedral.

This spectacular bridge is part of an abandoned train line that once connected Mallorcan capital to the southeastern coast.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

This Roman arch marks the location of an ancient gate at one of the Seven Hills of Rome.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

Where Venice's gondolas go for a tune-up.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

Two stone columns flank the grand Venice square, but there were supposed to be three.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

The solemn exterior conceals an opulent interior of this 17th century church.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

Baroque celebration of the end of the Great Plague of Vienna.